Electric-circuit closer for fire-alarms.



No. 767,625. PATENTED AUG. 16, 1904.. J. E. BEMILLER & E. C. WEISENSALE. ELECTRIC CIRCUIT CLOSER FOR FIRE ALARMS.

APPLICATION FILED MAY 'I, 1904. I

NO- MODEL:

U x m m a m UNITED STATES latented August 16, 1904.

PATENT QFFICE.

JOHN E. BEMILLER AND EMERY C. WVEISENSALE, OF HANOVER, PENNSYLVANIA.

ELECTRIC-CIRCUIT CLOSER FOR FIRE-ALARMS.

SPECIFICATION forming part of Letters Patent N0. 767,625, ated Aug st 16, 1904.

Application filed May 7, 1904. Serial No 206,954. (No model.)

To all whom (it may concern:

Beit known that we, JOHN E. BEMILLER and EMERY C. VVnIsnNsALE, of Hanover, in the county of York and State of Pennsylvania, have invented certain new and useful Improvements in Electric-Circuit Closers for Fire- Alarms; and we do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

Our invention relates to an improved electric-circuit closer for tire-alarms, the object of the invention being to provide a device of this character which will remain operative for an indefinite period and not become injured or broken by reason of oxidation of large metal contacts and which will be so constructed as to prevent breaking due to great expansion of the liquid expansive agent by reason of excessive heat and even though the heat be suliicient to break the bulb the circuit will be maintained closed; and with these and other objects in view the invention consists in certain novel features of construction and combinations and arrangements of parts, as will be more fully hereinafter described, and pointed out in the claims.

In the accompanying drawings, Figure l is a view in elevation, illustrating our improvements; and Fig. 2 is a view in longitudinal section, showing the parts exaggerated.

1 represents any suitable support for our improved cireuit-closer 2, which comprises a glass or other suitable transparent tube having a bulb or reservoir 3 at or near its lower end for mercury or other expansive agent and also provided with a smaller bulb or chamber 4 near its upper end to allow for undue expansion of the mercury Without constructing the tube of undue length.

Into the lower end of the tube 2 and extending up through the bulb 3 into the main portion of the tube is a Wire 5, insulated through its length in the tube with a coating 6, of glass or like material, leaving only the extreme end or the wire exposed to make electrical contact with the mercury for a purpose which will hereinafter appear. Into the upper end of the tube 1 and extending down therein the desired distance is another electric wire, 7, insulated like wire 6 throughout its length in the tube, leaving only the extreme end of the wire exposed to make electrical contact.

In circuit-closers of this character as heretoi'ore made the electric contacts are of such size and exposure as to become oxidized by contact with the mercury or vapors thereof to such an extent as to result in rendering the device inoperative either by closing the electric circuit, causing the alarm to be sounded continuously and necessitating the replacing of the circuit-closer by a new one, or the formation has been such as to cause the breaking of the tube when the mercury falls or rises materially. Another defect of similar devices heretofore made is that in the event of sudden rise of temperature the mercurybulb will be broken and the mercury escape without closing the electrical circuit. lVith our improvements all these objectionable features of former devices are overcome. By insulating the electric wires in the tube, leaving the extreme end only of the wires exposed, the metallic surface is so small as to prevent possibility of dangerous oxidation, and as the lower wire extends up through the bulb into the main portion of the tube even should the bulb be broken by a sudden rise of temperature the fact that there is a vacuum in the tube above the mercury therein will cause such mercury as connects the circuit between the contact-points to maintain the circuit closed and sound the alarm continuously. It will thus be seen that our improved device is a vast improvement in the art by reason of its not being liable to become inoperative by reason of oxidation, not liable to be broken by high temperatures, and even though it should be broken by direct contact with flame or excessive temperature the electric circuit will be maintained closed and sound an alarm.

Slight changes might be made in the general form and arrangement of the parts de scribed without departing from our invention, and hence we would have it understood that we do not restrict ourselves to the precise details set forth, but consider ourselves at liberty to make such slight changes and alterations as fairly fall within the spirit and scope of our invention.

Having fully described our invention, what we claim as new, and desire to secure by Letters Patent, is

1. In a circuit-closer, the combination with a tube having a bulb therein adjacent to its lower end, an expansive fluid in said tube, an electric wire projecting into the expansive fluid and insulated from contact with the fluid except at one end, and a similarly-insulated electric wire extending into the upper end of said tube.

2. In a circuit-closer of the character described, the combination with a tube having a bulb adjacent to its lower end, an expansive agent in said tube, an insulated electric wire extending through the lower end of the tube up through the bulb into the main portion of the tube and an insulated electric wire extending down into the tube from its upper end.

3. In a circuit-closer, the combination with a tube having a bulb adjacent to its lower end and an expansion-chamber near its upper end, of an expansive fluid in said tube, and insulated electric wires projecting into opposite ends of the tube and adapted to be electrically connected by the fluid in the tube upon the rise of temperature to a predetermined extent.

In testimony whereof we have signed this specification in the presence of two subscribing witnesses.

JOHN E. BEMILLER. EMERY C. WEISENSALE.

Witnesses:

HOWARD SLAGLE, E. H. WALTER. 

